This invention relates to light monitors for such as a CO2 laser light.
Heretofore, such a light monitor detects a part of the light by a sensor. It is necessary to attenuate the level of light to be in the range of the sensor. For this purpose, laser light is reflected by a rough surface or net surface. However, an uneven variation (i.e., mottle) in the level of light due to the reflected part is large. Attenuation by a slit or iris produces an uneven variation of light due to the interference diffraction of light.
This invention intends to eliminate these drawbacks, and an object of this invention is to provide a light monitor in which the light is attenuated to provide even light without any mottling and is able to monitor or measure light accurately by a device that is simple and small in construction.
One embodiment of this invention is a light monitor in which a beam splitter 4 is fixed on a base 1 in main beam 2 of a light system, a reflecting mirror 5 is fixed on a side of beam splitter 4, and inlet 6a of an integrating sphere 6 is provided at an opposite side of beam splitter 4. Light sensor 8 is provided at the reflecting surface of integrating sphere 6 in which main beam 2 is effectively attenuated by the reflection in beam splitter 4, mirror 5 and integrating sphere 6 and becomes even intensity light by multiple reflections in integrating sphere 6 for accurate monitoring.
This invention is also a light monitor in which movable reflector 7 is provided that is movable along the reflecting surface of integrating sphere 6.
This invention is also a light monitor in which beam splitter 4 is fixed on base 1 in a main beam 2 of a light system, reflected light from beam splitter 4 enters integrating sphere 6 when the attenuation rate is large and light sensor 8 is provided at the reflecting surface of integrating sphere 6.
This invention is also a light monitor in which a visible light system is provided in main beam 2 light system and visible light 11 superimposes with said main beam 2 for observation.
The above and other objects, advantages and novel features of this invention will be more fully understood from the following detailed description and the accompanying drawings, in which like reference numbers indicate like or similar parts throughout wherein;